The present invention relates to a system for the treatment of disorders of the vasculature, particularly aneurysms. An aneurysm is a medical condition indicated generally by an expansion and weakening of the wall of an artery of a patient. Aneurysms can develop at various sites within a patient's body. Thoracic aortic aneurysms (TAAs) or abdominal aortic aneurysms (AAAs) are manifested by an expansion and weakening of the aorta which is a serious and life threatening condition for which intervention is generally indicated. Existing methods of treating aneurysms include invasive surgical procedures with graft replacement of the affected vessel or body lumen or reinforcement of the vessel with a graft.
Surgical procedures to treat aneurysms can have relatively high morbidity and mortality rates due to the risk factors inherent to surgical repair of this disease, as well as long hospital stays and painful recoveries. Due to the inherent risks and complexities of surgical repair of aortic aneurysms, endovascular repair has become a widely used alternative therapy, most notably in treating AAAs. Early work in this field is exemplified by Lawrence, Jr. et al. in “Percutaneous Endovascular Graft: Experimental Evaluation”, Radiology (May 1987) and by Mirich et al. in “Percutaneously Placed Endovascular Grafts for Aortic Aneurysms: Feasibility Study,” Radiology (March 1989). Commercially available endoprostheses for the endovascular treatment of AAAs include the Endurant® stent graft system manufactured by Medtronic, Inc. of Minneapolis, Minn., the Zenith® stent graft system sold by Cook, Inc. of Bloomington, Ind., the PowerLink® stent graft system manufactured by Endologix, Inc. of Irvine, Calif., and the Excluder® stent graft system manufactured by W. L. Gore & Associates, Inc. of Newark, Del. A commercially available stent graft for the treatment of TAAs is the TAG™ system manufactured by W. L. Gore & Associates, Inc.
When deploying such endovascular devices by catheter or other suitable instrument, it is advantageous to have a flexible and low profile stent graft and delivery system for passage through the various guiding catheters as well as the patient's sometimes tortuous anatomy. Many of the existing endovascular devices and methods for treatment of aneurysms, while representing significant advancement over previous devices and methods, use systems having relatively large transverse profiles, often up to 24 French. The profile of stent grafts may be important to achieve a favorable clinical result.
Traditional stent graft systems incorporate a full metal ring at one end of the graft, to which a stent may be attached. Although this provides securement of the stent to the graft end, it is difficult to compress the stent graft to a small size for delivery. What has been needed are stent graft systems and methods that are capable of being compressed to a small size and can be safely and reliably deployed using a flexible low profile system.